Gas turbine engines, such as those used in commercial aircraft, utilize a compressor, combustor and turbine section arranged sequentially in an engine core to generate thrust and propel the aircraft forward. During operation of the gas turbine engine multiple variables are measured and detected via sensors disposed circumferentially about the turbine engine. This sensor arrangement is referred to as a sensor ring. The sensed variables can include turbine exhaust temperatures, exhaust pressures, or any other necessary variable. While the instant disclosure discusses turbine exhaust variables specifically, it is understood that the same method can be applied to any similar system including augmenter inlets and exhausts.
One metric measured during operation of the gas turbine engine is the turbine exhaust temperature and/or the power turbine inlet temperature. These temperature measurements are utilized to ensure that the gas turbine engine operates within the allowable safe average temperature limits of the engine. When the turbine engine exceeds the allowable safe average temperature for longer than a pre-defined period of time, the turbine engine must be removed from the wing and undergo maintenance or be replaced. As described above, these temperature measurements are typically made using multiple temperature sensors that are disposed evenly circumferentially about a sensor ring at the turbine exhaust or at the power turbine inlet. This measurement scheme provides an “average” temperature of the gasses passing through the turbine exhaust or the power turbine inlet.
In practice, turbine engine designs utilize multiple fuel nozzles disposed circumferentially about a combustor to inject fuel into the combustor. As a result of the fuel nozzle placement, the temperature profile at the turbine exhaust or at the power turbine inlet is not even circumferentially. As the sensors are disposed evenly circumferentially, and the temperature profile is not even circumferentially, the determined average is skewed, and can be off by as much as 150-200 degrees Fahrenheit.